The sandwich wire antenna: A new type of microwave line source radiator

Two new types of microwave antennas have been invented. The first consists of an undulating conductor surrounded by straight conductors at ground potential. When the period of undulation is a wavelength long, transversely-polarized broadside radiation is obtained. Various modifications of this basic configuration result in two-dimensional pencil beam arrays, in line sources for secondary reflectors and lenses, and in antennas suitable for printed circuit techniques. The second type of antenna is a cylindrical structure which has a nondirectional azimuthal pattern. It consists of a central helical conductor surrounded by a coaxial metallic cylinder in which longitudinal or transverse slots, also helically disposed, are cut. Its elevation pattern is narrow and depends upon the length of the array. Distributive methods of matching these traveling wave arrays for broadside radiation and means of controlling the radiation intensity are described. Possible fields of application are in radar, communications and television.